Freshwater aquarium fish, an important food source in the tropics
May 5, 2005
Those fish in your home aquarium may be important food sources in their native lands. According to figures recently released by the United Nations Food and Agriculture Organization’s (FAO) Fisheries Department many fish typically kept by aquarium owners figure significantly in the daily nutrition of people in tropical Africa, Asia, and South America. There’s something to consider the think about the next time you pick up new pets at your local fish store.
In South America many of the larger catfish (algae-eating Plecos and shovel-nosed catfish), characins (like Pacus and headstanders), and cichlids (Oscars, peacock bass) are widely harvested from rivers by local people. The Oscar, a popular ornamental fish in aquaria worldwide, is fished extensively in its Amazon home. In 2002, FAO estimates that around 183 metric tons of Oscars were taken out of rivers and streams in South America. In comparison, in Africa some 12,567 metric tons Mormyrids — a family which includes the elephant-nosed fish — were harvested from inland waters in 2002.
The Arowana (Osteoglossum bicirrhosum) is a popular tropical freshwater aquarium species. You can learn more about the Arowana here
Overfishing is a problem in some freshwater habitats — even the enormous Amazon river suffers from over exploitation of its fisheries. For example, the Arapaima which in the past was regularly found to exceed 10 feet in length (3 m) is rarely encountered today at a size greater than 8 feet (2.45 m).
Commercial Fishing in the Amazon: A case study
In the mid 1980s, the FAO Fisheries Department did a case study on fishing in the Amazon. The study, contained within Management systems for riverine fisheries by Thayer Scudder and Thomas Conelly, found a rapidly developing commercial fishery which involved both traditional fishermen and outsiders. The growth of the Amazonian fishing industry in the case study coincided with the completion of the Trans-Amazon highway in the early 1970s which caused the population of newly connected Amazon towns to burgeon. The resulting population increase produced new demand for protein that was met by the expansion of fishing operations on the Amazon and its surrounding tributaries.
The authors note that “During the same period, more sophisticated types of fishing gear, most importantly nylon gill and seine nets, were introduced into the area. In addition, with the growing local and export market for fish products, ice plants were opened to help in the preservation of fish for long distance shipment… [and] large-capacity motorized fishing vessels were also introduced.” The result, a significant increase in the productivity of the fisheries. However, this gain was short-lived. The authors conclude that “though there is apparently no evidence that heavily exploited fish species are in danger of extinction over the region as a whole, local depletion of commercially important species has become a problem and the productivity of fisheries in the Amazon has dropped significantly after an initial boom during the late 1960s and early 1970s.”
The expansion of commercial fishing activities may have also affected the catch by subsistence or artisanal fishermen among the local indigenous communities.
To learn more about the FAO’s findings, take a look at http://www.fao.org/documents/show_cdr.asp?url_file=/DOCREP/003/X6848E/X6848E00.HTM
Below is capture production data for some selected aquarium species and types of tropical freshwater fish. All figures from the FAO’s Review of the State of World Marine Fishery Resources.
|REGION / SPECIES||(All figures in metric tonnes)||1996||1997||1998||1999||2000||2001||2002|
|Nile tilapia||Oreochromis niloticus||177,072||157,714||188,056||175,846||204,350||205,353||207,572|
|Tilapias nei||Oreochromis (=Tilapia) spp||157,482||169,253||171,638||196,812||210,928||218,209||213,412|
|Mouthbrooding cichlids||Haplochromis spp||10,472||13,053||13,077||10,731||11,699||9,695||8,759|
|Upsidedown catfishes||Synodontis spp||9,267||11,560||13,384||12,856||12,571||13,737||12,827|
|Velvety cichlids||Astronotus spp||308||177||141||251||188||183||…|
|Glass catfishes||Kryptopterus spp||17,560||15,938||13,943||15,927||13,110||13,522||14,980|
|Pangas catfishes nei||Pangasius spp||541||522||917||1,061||1,274||1,100||1,200|
|Climbing perch||Anabas testudineus||3,905||3,754||4,637||6,340||6,730||5,800||6,300|
|Snakeskin gourami||Trichogaster pectoralis||30,792||21,728||22,422||23,776||22,456||21,357||20,940|
|Kissing gourami||Helostoma temminckii||12,611||18,376||16,598||23,320||18,771||19,429||20,140|
|Striped snakehead||Channa striata||30,966||28,646||21,520||23,784||26,839||24,998||25,988|
|Indonesian snakehead||Channa micropeltes||11,614||10,117||8,253||8,787||8,149||6,357||6,440|